Traditionally in hairstyle applications, hair-conditioning agents in the form of hair setting liquids, aerosol and non-aerosol sprays, and hair styling foams and gels have been used. While polymers may serve hair setting and thermal insulating functions in the existing conditioning agents, these polymers may be easily washed off, and thus greatly diminish their setting properties.
Shape memory materials have drawn wide attention because of their ability to recover their original shapes upon exposure to an external stimulus. Shape memory materials can find applications in sensors, actuators, smart devices, and media recorders. Examples of shape memory materials may include shape memory alloys, shape memory ceramics, and shape memory polymers.
Traditional shape memory polymers use elastic polymer networks that are equipped with stimuli-sensitive switches. The driving force for shape recovery in these shape memory polymers has usually been the elastic strain that is generated by deformation or by raising the surrounding temperature above the response temperature of the polymers. Deformation at high temperature may be easier to achieve due to the low rubbery modulus of the polymers that may make the orientation of the polymer more feasible. However, the orientation may become partly relaxed before the structure can be frozen during subsequent cooling cycles. On the other hand, deformation at low temperature is difficult due to the high glassy state modulus of the polymers. Shape memory polymers as applied in conditioning agents have been not satisfactorily carried out.
Consequently, it is desirable to have an improved method of applying hair-conditioning agent to impart a shape memory effect to hair. It is also desirable to have the improved hair-conditioning agent such that a hairstyle is more lasting, is retrievable to the set hairstyle when the hairstyle is altered, and the agent is easily removable when finished. It is further desirable to characterize the shape memory effect in hair in two dimensions and three dimensions.